Seasonal Shifts in Cold Tolerance and the Composition of the Gut Microbiome of Dendroctonus valens LeConte Occur Concurrently

Dendroctonus valens LeConte, an invasive bark beetle, has caused severe damage in pine forests and has the potential to disperse into new geographic ranges in China. Although the gut microbiota of D. valens and its fundamental role in host fitness have been investigated widely, little is known about the relationship between the seasonal shifts of both cold tolerance and the gut microbiome of D. valens during overwintering, which occurs at the larval stage. In this study, to examine seasonal variations in the composition of the microbiome, we collected D. valens larvae in September (autumn), January (winter), and May (spring), and then analyzed the bacterial and fungal communities of the gut via sequencing of partial 16S rRNA and ITS genes. In addition, changes in the supercooling capacity and antioxidant enzyme activities of D. valens larvae collected in the different seasons were evaluated. Overwintering resulted in changes to microbial communities. In particular, the abundances of Enterobacter, Serratia, Erwinia, and Klebsiella decreased during overwintering. Concurrent with these changes, the cold tolerance of D. valens larvae was enhanced during overwintering, and the activities of the antioxidant enzymes catalase and peroxidase were reduced. We hypothesize that seasonal shifts in the gut microbiome may be connected to changes in cold tolerance and antioxidant enzyme activity in D. valens. It will be worthwhile to confirm whether seasonal changes in the microbiome contribute to the success of host overwintering.

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THE RELATIONSHIP AMONG IMMUNE RESPONSE TO SRBC ANTIGEN AND SOME ENDOGENOUS ANTIOXIDANT ENZYME ACTIVITIES IN CHICKENS

Menoufia Journal of Animal Poultry and Fish Production ◽

10.21608/mjapfp.2019.174811 ◽

2019 ◽

Vol 3 (3) ◽

pp. 83-97

Author(s):

A. A. El-Fiky ◽

G. M. Gebriel ◽

F. H. Abdou ◽

M. Kahiel

Keyword(s):

Immune Response ◽

Antioxidant Enzyme ◽

Enzyme Activities ◽

Antioxidant Enzyme Activities ◽

Endogenous Antioxidant ◽

The Relationship

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RELATIONSHIP BETWEEN ENDOGENOUS SALICYLIC ACID AND ANTIOXIDANT ENZYME ACTIVITIES IN MAIZE SEEDLINGS UNDER CHILLING STRESS

Experimental Agriculture ◽

10.1017/s0014479712001329 ◽

2013 ◽

Vol 49 (2) ◽

pp. 295-308 ◽

Cited By ~ 7

Author(s):

YANG WANG ◽

TINGTING WEN ◽

JIN HU ◽

RUI HAN ◽

YANFANG ZHU ◽

...

Keyword(s):

Salicylic Acid ◽

Antioxidant Enzymes ◽

Antioxidant Enzyme ◽

Enzyme Activities ◽

Chilling Stress ◽

Antioxidant Enzyme Activities ◽

Maize Seedlings ◽

Stress Changes ◽

Positive Correlations ◽

The Relationship

SUMMARYSalicylic acid (SA) can induce multiple stress tolerance in plants. This study investigated the relationship between SA and antioxidant enzyme activities in maize seedlings under chilling stress. Changes of endogenous SA, antioxidant enzyme activities and malondialdehyde (MDA) concentrations were assessed in two different chilling-tolerant maize inbred lines (Huang C and Mo17) under chilling stress. The results showed that both endogenous free and bound salicylic acid contents increased in roots and leaves of both lines. MDA concentrations also increased significantly in roots and leaves of both lines after chilling stress. In addition, in Huang C, chilling stress increased the activities of four antioxidant enzymes, ascorbate peroxidase (APX), catalase (CAT), glutathione reductase (GR) and peroxidase, while in Mo17, only CAT and APX increased. Furthermore, a regression analysis was conducted between SA and MDA concentrations or antioxidant enzyme activities under chilling stress. The results indicated that MDA concentrations were positively correlated with total SA contents in roots (r = 0.9776, p = 0.0224) and bound SA in leaves (r = 0.9974, p = 0.0458), respectively. Total SA contents had positive correlations with APX activities both in roots (r = 0.9993, p = 0.002) and leaves (r = 0.9630, p = 0.037) and GR in leaves (r = 0.9298, p = 0.0221). Together, these results suggested that chilling stress improved the biosynthesis of endogenous SA, and lipid peroxidation and antioxidant enzyme activities could be indicated by endogenous SA contents of maize seedlings under chilling stress. Furthermore, increased activities of antioxidant enzymes, especially in roots, may contribute to the chilling tolerance of maize seedlings.

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Skeletal muscle oxidative capacity, antioxidant enzymes, and exercise training

Journal of Applied Physiology ◽

10.1152/jappl.1990.68.6.2337 ◽

1990 ◽

Vol 68 (6) ◽

pp. 2337-2343 ◽

Cited By ~ 146

Author(s):

M. H. Laughlin ◽

T. Simpson ◽

W. L. Sexton ◽

O. R. Brown ◽

J. K. Smith ◽

...

Keyword(s):

Skeletal Muscle ◽

Antioxidant Enzymes ◽

Exercise Training ◽

Antioxidant Enzyme ◽

Oxidative Capacity ◽

Antioxidant Enzyme Activities ◽

Sprague Dawley ◽

Muscle Oxidative Capacity ◽

Sprague Dawley Rats ◽

The Relationship

The purposes of this study were to determine whether exercise training induces increases in skeletal muscle antioxidant enzymes and to further characterize the relationship between oxidative capacity and antioxidant enzyme levels in skeletal muscle. Male Sprague-Dawley rats were exercise trained (ET) on a treadmill 2 h/day at 32 m/min (8% incline) 5 days/wk or were cage confined (sedentary control, S) for 12 wk. In both S and ET rats, catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPX) activities were directly correlated with the percentages of oxidative fibers in the six skeletal muscle samples studied. Muscles of ET rats had increased oxidative capacity and increased GPX activity compared with the same muscles of S rats. However, SOD activities were not different between ET and S rats, but CAT activities were lower in skeletal muscles of ET rats than in S rats. Exposure to 60 min of ischemia and 60 min of reperfusion (I/R) resulted in decreased GPX and increased CAT activities but had little or no effect on SOD activities in muscles from both S and ET rats. The I/R-induced increase in CAT activity was greater in muscles of ET than in muscles of S rats. Xanthine oxidase (XO), xanthine dehydrogenase (XD), and XO + XD activities after I/R were not related to muscle oxidative capacity and were similar in muscles of ET and S rats. It is concluded that although antioxidant enzyme activities are related to skeletal muscle oxidative capacity, the effects of exercise training on antioxidant enzymes in skeletal muscle cannot be predicted by measured changes in oxidative capacity.

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